The Flow Rate of the Condenser Cooling Water in the Distillation Process Increases the Quality and Quantity of Patchouli Oil

Indonesia is an important essential oil-exporting country globally, where 40 types of essential oils have been traded on the international market and are products of Indonesia. However, the quality and quantity of patchouli oil produced in Indonesia are still low. Most essential oil processing units use simple or traditional technology and generally have limited production capacity. This study aimed to obtain the optimum water flow rate in a condenser system for patchouli oil production in Maluku, Indonesia. Patchouli oil extraction from fresh patchouli leaves and twigs was carried out by increasing the condenser water discharge rate. Patchouli oil extraction with a condenser cooling water discharge treatment of 1.74 L/min and drying time for 5 days produced the highest patchouli oil yield of 1.4%. The greater the condenser water discharge rate, the better the yield and accumulation of patchouli oil recovery obtained. In addition, based on the results of the analysis of the composition of patchouli oil compounds with GCMS, it can be seen that 13 compounds can be detected in patchouli oil. The three main components of patchouli oil in all condenser cooling water treatments were alpha-guaiene, delta-guaiene, and patchouli alcohol. Considering the results of all parameters mentioned above, the treatment of the condenser cooling water discharge of 1.74 L/min and drying time for 5 days increases the quality and quantity of patchouli oil.


Introduction
Indonesia is an agricultural country with extraordinary natural wealth and abundance of various types of plants.As one of the most critical essential oil-exporting countries in the world, 40 types of essential oils traded on the international market are products of Indonesia [1].Essential oil-producing plants that have market opportunities include patchouli.Te Pogostemon genus is estimated to have 40 species, but patchouli is the only species with market opportunities [2].Patchouli (Pogostemon cablin) comes from the Lamiaceae family.It is one of the essential oil-producing plants from tropical Asia.It is cultivated in the Caribbean, China, India, Indonesia, and the Philippines, as well as in several states of Karnataka, Gujarat, and Assam in India [3,4].Patchouli oil obtained by distilling the leaves of Pogostemon cablin Benth contains more than 24 diferent sesquiterpenes [5].Tis oil is widely used in the perfume, soap, pharmaceutical, and cosmetic industries [6] or as aromatherapy which can heal physically, mentally, and emotionally [7].Te addition of oil with the patchouli alcohol component to perfume can maintain the aroma of perfume for a long time because of its function as a binder that cannot be replaced by any oil [8,9], so it is essential in making perfume [10].Patchouli oil also has pharmacological efects, including antibacterial, antifungal, antiemetic [11,12], anti-infuenza [13], antioxidant [14], antimicrobial [15,16], irritation, skin infammation, bioinsecticide [17], and anticancer activities [18][19][20].However, the quality and quantity of patchouli oil produced in Indonesia still need improvement.Most essential oil processing units use simple or traditional technology and generally have limited production capacity.
One factor afecting patchouli oil production is postharvest handling and extraction methods.In Indonesia, oil is extracted from patchouli leaves and twigs by distillation [21].Diferent distillation methods afect the oil yield [22]. Steam distillation is a traditional method for obtaining patchouli oil [23,24].Te hydrodistillation process takes a long time and will afect the degradation of patchouli oil molecules [25].One technology that is proven to increase oil yield through distillation is the cooling condenser technology.Te cooler (water condenser) is a vital heat exchanger in refning patchouli oil because it condenses the steam [26].Te low oil yield can be caused by various factors, including the performance of the heat exchanger (condenser) that could be more optimal.Te efectiveness of the condenser is infuenced by several factors, including condenser design, condenser water temperature, material conductivity, and other factors [27].Color change, chemical-physical properties, essential oil yield, and distillation speed are afected by the water temperature in the condenser because it is related to the speed of steam condensation in the cooling pipe.Several related studies have shown that water as a condenser coolant cools the condenser faster than air [28].Te performance of the shell and tube condenser is infuenced by the heat exchanger's design, the fuid's mass fow rate, the conductivity value of the heat exchanger material, the insulation density, and the temperature and ambient temperature [29].Te research results of Ahmad and Anis [30] show that the greater the cooling water discharge in the condenser, the higher the yield of distilled pine resin oil and the greater the heat transfer rate, which causes the condenser to cool [31].On the other hand, if the cooling water velocity decreases, the condenser water temperature increases, which afects the heat transfer rate [32].
Patchouli oil refning in Maluku, Indonesia, uses a water steam distillation system and a traditional heat exchanger (condenser).Tis refning resulted in a low yield of patchouli oil due to the not-yet-optimal distillation process technology and the performance of the heat exchanger (condenser) device.For this reason, obtaining a better distillation system is necessary to increase the yield and quality of patchouli oil.Terefore, this study aims to obtain the optimum water fow rate in a condenser system for patchouli oil production in Maluku, Indonesia.

Plant Materials.
Fresh patchouli leaves and twigs used in this study were Aceh patchouli (Pogostemon cablin Benth) taken from patchouli oil farmers/refners from Taeno village, Keranjang village, Ambon District, Maluku Province, Indonesia.Leaves and twigs of Pogostemon cablin were collected in June 2021 and stored at room temperature.

Pogostemon cablin Extraction.
Patchouli leaves and twigs that were cut into smaller pieces were dried in the sun for two days and dried under the shade for 5 (B 1 ), 6 (B 2 ), and 7 days (B 3 ) and then distilled using the steam and water distillation method.Te treatment of condenser cooling water discharge was based on the study by Smith et al. [33] with modifcations, namely, 1.74 (A 1 ), 1.08 (A 2 ), and 0.48 liter/minute (A 3 ).Te distilled apparatus was made of stainless steel with a capacity of 8 kg.Te distillation duration was based on the amount of patchouli raw material being distilled, and distillation was stopped if no oil came out simultaneously with the condensate water (±3 hours) [34].Te response variables measured were the oil yield, condensate fow rate, condenser water temperature, and patchouli alcohol content.Te term condensate fow rate in this study is the rate of steam fuid condensing in the condenser pipe that comes out in the form of a mixture of patchouli oil and water.In addition, the content of compounds in patchouli oil was measured using GCMS.Te equipment used includes steam-water distillation equipment consisting of a boiler and condenser, stove (as heater), separator, and laboratory equipment for patchouli oil testing.In the condenser, cooling water was circulated using a circulation pump.In addition, the equipment used in this study included a distillation kettle with a flling volume of 0.023 m 3 of patchouli leaves, a water-cooled condenser with a spiral-shaped heat exchanger type with a cold fuid volume of 0.022 m 3 , and a separator (Figure 1).Te research was conducted at the Ambon Industrial Standardization and Research Institute, Indonesia.

Determination of Patchouli Alcohol in Patchouli Oils.
Patchouli alcohol was determined according to the method described by Kongkathip et al. [15].Te sample volume was 2 μL.Patchouli alcohol concentration was calculated on the basis of the linear calibration function.Te content of patchouli alcohol was expressed as grams per 100 g of dry weight.

Patchouli Oil Component Identifcation. A gas chromatography-mass spectroscopy (GCMS) technique was used to analyze the chemical composition of patchouli oil. GCMS analysis used gas chromatograph Merck Agilent
Technologies Type 7890 B with a nonpolar column, namely, HP-1 MS (methyl siloxane), with specifcations of 30 m × 25 μm × 0.25 μm.Te oven temperature was held constant at 60 °C for 1 min and then increased to 220 °C with a temperature increase rate of 30 °C/min.Te fnal oven temperature was then kept constant for 4 min.Te injector, transfer line, and detector temperatures were 250, 240, and 230 °C, respectively.Ionization energy was 70 eV, and the fow rate of carrier gas (helium) was 1 ml/min.Te samples (1% v/v in hexane) were injected into GC by split mode with 2 Te Scientifc World Journal a split ratio of 1/100.Patchoulol identifcation and other volatile compounds were based on comparing the mass spectra obtained in the gas chromatograph with those obtained from the GCMS library and literature [35][36][37][38].

Statistical Analysis.
Experiments were performed using a completely randomized factorial design with three replications.Means were compared by one-way analysis of variance and Duncan's multiple range test (DMRT) at a 5% signifcance level.Data are presented as the mean.

Te Condensate Flow Rate and Condenser Water
Temperature.Te treatment of condenser cooling water discharge and the drying time of patchouli afected the condensate fow rate.Distillation of patchouli leaf oil, which was dried under the shade for fve days (B1), resulted in a condensate fow rate of 34.67, 29.33, and 24.33 ml/min for the treatment of A1, A2, and A3 condenser cooling water discharge, respectively (Table 1).Te treatment of the condenser cooling water discharge of 1.74 L/min and drying for fve days on patchouli leaves resulted in the highest condensate fow rate, which was 2.17-fold faster than the condenser cooling water discharge of 0.48 L/min and drying for seven days (general conditions to produce patchouli oil in farmers/refners).Te decrease in the condensate fow rate is due to the reduced condenser cooling water discharge caused by the diference in the velocity of steam fuid condensing into the liquid fuid in the condenser pipe.Te high discharge of condenser cooling water causes a faster heat transfer of the steam fuid in the condenser pipe.Te higher the condenser cooling water discharge, the faster the process of condensing the liquid vapor from the condenser into a liquid (a mixture of oil and water).Cooling water discharge afects the condenser's heat transfer rate [27].Te faster the fow rate of the coolant, the faster the heat transfer rate occurs in the condenser [29].
Determination of condenser water temperature showed that there were diferences in each treatment of condenser water discharge and drying time of patchouli leaves.Te lowest condenser water temperature was 30.56 °C in the patchouli oil distillation treatment.Te condenser cooling water discharge was 1.74 L/min with the leaves drying time for 5 days (Table 2).Te smaller the cooling water discharge, the higher the condenser water temperature.Tis is caused by diferences in the heat transfer of water contained in the condenser shell in each treatment of cooling water discharge.Te condenser water temperature is afected by the discharge of the condenser cooling water in the essential oil production process [29,30].Te efect of temperature on the yield is detrimental, where under isobaric conditions, an increase in temperature reduces the density of supercritical CO 2 , thereby reducing the solubility of the fuid [39].However, a higher temperature increases the vapor pressure of the solute, making oil more accessible to extract [40].In addition, an increase in temperature causes antioxidants and bioactive compounds that are sensitive to an increase in temperature to be degraded [41].Tis harms the antioxidant activity.Terefore, in this study, the condenser cooling water discharge treatment of 1.74 and 1.08 L/min inhibited the increase in condenser water temperature.

Patchouli Oil.
Te results of the distillation of patchouli oil using steam and water distillation and with a shell and tube-type heat exchanger (condenser) showed diferences in the yield of patchouli oil produced in the condenser release treatment and the drying time of patchouli leaves.Te greater the condenser water discharge during distillation, the greater the patchouli oil yield (Table 3).However, the longer the leaves were exposed to the sun, the lower the yield of patchouli oil (Table 3).Distillation of oil from patchouli leaves in the treatment of condenser cooling water discharge of 1.74 l/min and drying time for 5 days resulted in a yield of patchouli oil of 1.4%, while the distillation of dried leaf oil for 5 days with condenser water discharge produced a higher yield of patchouli oil was 0.37% and 1.06% for the treatment of condenser water discharge of 1.08 and 0.48 l/min, respectively (Table 3).Te diference in the yield of patchouli oil in each treatment showed the contribution of the condenser cooling water debit and drying of the leaves to the patchouli oil yield.Te condenser water discharge signifcantly afects the amount of pine resin oil produced; the higher the condenser cooling water discharge, the higher the pine resin oil produced [27].Te higher the condenser cooling water discharge, the faster the heat transfer rate from the hot steam fuid in the tube/pipe to the cooling water in the shell.Water-cooled condensers cool the condensers faster than air-cooled condensers [28].
Patchouli alcohol is the main component of patchouli oil [5,42].Te alcohol content of patchouli oil is usually used as a reference for assessing the quality of patchouli oil [43]; the higher the content of these compounds in patchouli oil, the better the quality [42].Te test results showed no diference in the alcohol content of the patchouli oil produced by the treatment of the condenser cooling water discharge and the drying time of the patchouli leaves.Te alcohol content of Te Scientifc World Journal patchouli oil is 16.84-17.30%(Table 4).Patchouli oil produced in Indonesia has an alcohol patchouli level of <30% because the handling of postharvest material before refning is not proper; the distillation process is not optimal due to the short distillation time and the infuence of the origin of the raw material.Terefore, alcohol patchouli content still needs to be increased to expand its market reach [43].

Patchouli Oil Component.
Te three main components of patchouli oil in all condenser cooling water treatments were alpha-guaiene, delta-guaiene, and patchouli alcohol (Table 5).In general, patchouli essential oil contains patchouli and sesquiterpenoid guaiene as the most exclusive class of compounds [44][45][46][47][48]. Te condenser cooling water treatment did not signifcantly afect the   4 Te Scientifc World Journal patchouli oil content (Table 5).Diferences in the components/composition of patchouli oil qualitatively and quantitatively are caused by diferences in environmental factors, areas of origin of samples, diferences in harvesting methods, postharvest processing, conditions of distillation, and oil storage [43].Te anti-infammatory potential of patchouli oil depends primarily on the class of compounds present in its volatile composition.Several guaiane-type compounds exhibit inhibitory efects on proinfammatory cytokines [49].Te guaiene content as an important component in essential oils ranges from 16.14 to 18.90% (Table 5).In addition, patchouli alcohol is also an essential compound in patchouli oil.Patchouli alcohol has been a predominant constituent [48] with the anti-infammatory, ulcerogenic, bacterial, and fungal activities [50,51].

Conclusions
Tis study confrmed that patchouli oil extraction with the treatment of a condenser cooling water discharge of 1.74 L/ min and drying time for 5 days produced the highest patchouli oil yield of 1.4%, the condensate fow rate of 34.67 ml/min, the condenser water temperature of 30.56 °C, and the patchouli alcohol content of 16.84%.Te greater the condenser water discharge rate, the better the yield and accumulation of patchouli oil recovery obtained.In addition, based on the results of the analysis of the composition of patchouli oil compounds with GCMS, it can be seen that 13 compounds can be detected in patchouli oil.Te three main components of patchouli oil in all condenser cooling water treatments were alpha-guaiene, delta-guaiene, and patchouli alcohol.Te Scientifc World Journal

Table 2 :
Te condenser water temperature on several treatments of condenser water discharge and patchouli leaf drying.Notes: the numbers followed by the same letter in the same column or the same capital letter in the same line indicate no signifcant diference by Duncan's multiple range test (P < 0.05).

Table 1 :
Te condensate fow rate on several treatments of condenser water discharge and patchouli leaf drying.Notes: the numbers followed by the same letter in the same column or the same capital letter in the same line indicate no signifcant diference by Duncan's multiple range test (P < 0.05).

Table 3 :
Oil yield on several treatments of condenser water discharge and patchouli leaf drying.Notes: the numbers followed by the same letter in the same column or the same capital letter in the same line indicate no signifcant diference by Duncan's multiple range test (P < 0.05).

Table 4 :
Patchouli alcohol content on several treatments of condenser water discharge and patchouli leaf drying.Notes: the numbers followed by the same letter in the same column or the same capital letter in the same line indicate no signifcant diference by Duncan's multiple range test (P < 0.05).

Table 5 :
Patchouli oil component on several treatments of condenser water discharge.